Reciprocating compressor

ABSTRACT

A reciprocating compressor, including a piston which performs a reciprocating movement by receiving a driving force of a reciprocating motor, a cylinder in which a piston is inserted to form compression spaces therein together with the piston, and an inclined discharging surface is formed at the end surface and a valve assembly including a discharging cover which is combined with a side of the cylinder, a discharging valve which is installed at an end of the cylinder to adjust gas discharge in the compression spaces and a valve spring for elastically supporting the discharging valve.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a reciprocating compressor and particularly, to a reciprocating compressor, capable of improving compression performance by improving structures of a discharging valve for adjusting discharge of gas and an end surface of the cylinder which is rubbed and contacted with the discharging valve.

[0003] 2. Description of the Background Art

[0004] Generally, a compressor is an instrument for compressing refrigerant gas under the condition of low temperature and pressure, which is introduced from an evaporator and discharging the gas by changing the condition to high temperature and pressure.

[0005] The compressor can be classified to a rotary compressor, reciprocating compressor and a scroll compressor according to the method of compressing fluid.

[0006] Particularly, the reciprocating compressor sucks and compresses fluid while a piston moves linearly, and such reciprocating compressor is divided into a method which compresses fluid by converting the rotary movement of a driving motor into a reciprocating movement of the piston, and a method which compresses and sucks fluid by having the piston perform a reciprocating movement as the driving motor performs a linear reciprocating movement.

[0007]FIG. 1 is a cross-sectional view showing a conventional reciprocating compressor, FIG. 2 is a partially cross-sectional view showing an operation state of a discharging valve assembly in operating suction of gas in FIG. 1 and FIG. 3 is a partially cross-sectional view showing an operation state of a discharging valve assembly in operating discharging of gas in FIG. 1.

[0008] As shown in the drawing, the conventional reciprocating compressor includes a case 10 having a gas suction pipe SP and gas discharging pipe DP, a frame unit 20 which is elastically installed inside the case 10, a reciprocating motor 30 for generating a driving force while being fixed on the frame unit 20, a compression unit 40 for sucking, compressing and discharging gas using a linear reciprocating force of the reciprocating motor 30 and a resonance spring unit 50 for inducing resonating movement by elastically supporting the compression unit 40 in the movement direction.

[0009] The frame unit 20 includes a front frame 21 for supporting the compression unit 40, a middle frame 22 which is combined with the front frame 21, for supporting the front side of the reciprocating motor 30, and a rear frame 23 which is combined with the middle frame 22, for supporting the rear side of the reciprocating motor 30.

[0010] The reciprocating motor 30 includes an outer stator 31 which is installed between the middle frame 22 and rear frame 23, an inner stator 32 which is combined with the outer stator 31 at a predetermined interval and is inserted and combined with the rear frame 23, and a movable element 33 which is installed between the outer stator 31 and inner stator 32, for performing a linear reciprocating movement.

[0011] The compression unit 40 includes a cylinder 41 which is integrally formed in the front frame 21, a piston 42 which is combined with the movable element 33 of the reciprocating motor 30, for performing a reciprocating movement in a compression space P1 of the cylinder 41, a suction valve 43 which is mounted at the front end of the piston 42, for restricting suction of gas opening and closing the suction path F of the piston 42 and a discharging valve assembly 70 which is mounted at the discharging side of the cylinder 41, for adjusting discharge of compression gas while opening and closing the compression space P1.

[0012] The discharging valve assembly 70 includes a discharging cover 71 for covering a side of the cylinder 41, a discharging valve 72 which is inserted inside the discharging cover 71, for opening and closing the compression space P1 of the cylinder 41 and a valve spring 73 which is supported on the inner side of the discharging cover 71 and is combined with the discharging valve 72, for elastically supporting the discharging valve 72 while setting the position of the discharging valve 72.

[0013] The operation process of the conventional reciprocating compressor with the above construction will be described as follows.

[0014] When a flux is formed between the outer stator 31 and inner stator 32 by applying a power source to the reciprocating motor 30, the movable element 33 of the reciprocating motor 3 elastically performs a reciprocating movement by the resonance spring unit 50.

[0015] At this time, as the piston 42 performs a reciprocating movement inside the cylinder 41, the volume of the compression space P1 is changed, and the gas is sucked and compressed.

[0016] As the pressure of the gas is higher than a predetermined pressure, when it becomes higher than an elastic force of the valve spring 73, the discharging valve 72 is moved. As the sequential process that the compression gas is discharged into the compression space P2 is repeated, the discharged gas by opening and closing of the discharging valve 72 is discharged to the outside through a gas discharging pipe DP which is formed in the discharging cover 71.

[0017] However, as shown as a wave-line in FIG. 2, conventionally, in case the compressor is operated for a long time, the discharging valve 72 is deformed by a pressure difference of the compression spaces P1 and P2 and abrasion is occurred at the contact portion by friction contact between the discharging valve 72 and cylinder 41.

[0018] In case the discharging valve is deformed and the end surface of the cylinder is worn away, the performance of the discharging valve 72 is degraded and accordingly the performance of the compressor is degraded.

SUMMARY OF THE INVENTION

[0019] Therefore, an object of the present invention is to provide a reciprocating compressor, capable of improving compression performance by improving structures of a discharging valve for adjusting discharge of gas and an end surface of the cylinder which is rubbed and contacted with the discharging valve.

[0020] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a reciprocating compressor, including a piston which performs a reciprocating movement by receiving a driving force of a reciprocating motor, a cylinder in which a piston is inserted to form compression spaces therein together with the piston, and an inclined discharging surface is formed at the end surface and a valve assembly including a discharging cover which is combined with a side of the cylinder, a discharging valve which is installed at an end of the cylinder to adjust gas discharge in the compression spaces and a valve spring for elastically supporting the discharging valve.

[0021] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

[0023] In the drawings:

[0024]FIG. 1 is a cross-sectional view showing a conventional reciprocating compressor;

[0025]FIG. 2 is a partially cross-sectional view showing an operation state of a discharging valve assembly in operating suction of gas in FIG. 1;

[0026]FIG. 3 is a partially cross-sectional view showing an operation state of a discharging valve assembly in operating discharging of gas in FIG. 1;

[0027]FIG. 4 is a longitudinal sectional view showing a reciprocating compressor in accordance with the present invention;

[0028]FIG. 5 is a partially cross-sectional view showing an operation state of a discharging valve assembly in performing gas suction in FIG. 4; and

[0029]FIG. 6 is a partial cross-sectional view showing an operation state of a discharging valve assembly in performing gas discharging in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[0031]FIG. 4 is a longitudinal sectional view showing a reciprocating compressor in accordance with the present invention, FIG. 5 is a partially cross-sectional view showing an operation state of a discharging valve assembly in performing gas suction in FIG. 4, and FIG. 6 is a partial cross-sectional view showing the operation state of a discharging valve assembly in performing gas discharging in FIG. 4.

[0032] As shown in the drawing, the reciprocating compressor in accordance with the present invention includes a case 10 having a gas suction pipe SP and gas discharging pipe DP, a frame unit 20 which is elastically installed inside the case 10, a reciprocating motor 30 for generating a driving force while being fixed on the frame unit 20, a compression unit 140 for sucking, compressing and discharging gas using a linear reciprocating force of the reciprocating motor 30 and a resonance spring unit 50 for inducing resonating movement by elastically supporting the compression unit 140 in the movement direction.

[0033] The compression unit 140 includes a cylinder 141 which is formed in the front frame 121, a piston 142 which is combined with the movable element 133 of the reciprocating motor 130, for performing a reciprocating movement in a compression space P1 of the cylinder 141, a suction valve 143 which is mounted at the front end of the piston 142, for controlling suction of gas opening and closing the suction path F of the piston 142 and a discharging valve assembly 170 which is mounted at the discharging side of the cylinder 141, for adjusting discharge of compression gas while opening and closing the compression spaces P1 and P2.

[0034] The discharging valve assembly 170 includes a discharging cover 171 which is formed to have a predetermined space, for covering a side of the cylinder 141 again, a discharging valve 172 which is inserted inside the discharging cover 171, for opening and closing the compression spaces P1 and P2 of the cylinder 141 and a valve spring 173 which is supported on the inner side of the discharging cover 171 and is combined with the discharging valve 172, for elastically supporting the discharging valve 172 while setting the position of the discharging valve 172.

[0035] As a characteristic of the present invention, an inclined discharging surface 141B is formed on the end surface of the cylinder 141. In other words, the inclined discharging surface 141B is formed on a cylinder discharging surface 141A which is adjacent to the inner circumferential surface of the cylinder 141 and is contacted on the compression space P1.

[0036] Also, the pressure supporting surface 172A is protruded and formed at a predetermined curvature on the rear surface of the discharging valve 172, which is abutted on the cylinder discharging space 141A of the cylinder 141.

[0037] The outer portion of the pressure supporting surface 172A is composed to be abutted on the inclined discharging surface 141B of the cylinder 141.

[0038] In the initial driving without deformation of the discharging valve 172, the outline of the pressure supporting surface 172A is linearly contacted with the inclined discharging surface 141B of the cylinder 141, and even if the discharging valve 172 is deformed by the operation for a long time, the outline of the pressure supporting surface 172A is also linearly contacted with the inclined discharging surface 141B of the cylinder 141.

[0039] In other words, even though the discharging valve 172 is deformed, the rear surface of the discharging valve 172 is formed at a predetermined curvature so that the end surfaces of the discharging valve 172 and the cylinder 141 are not rubbed and contacted, and the inclined discharging surface 141B is formed at an end surface of the cylinder 141.

[0040] The operation effect of the reciprocating compressor with the above construction will be described as follows.

[0041] When the gas is sucked into the compression space P1 and compressed while varying the volume of the compression space P1 as the piston 142 performs a reciprocating movement inside the cylinder 141, the pressure of the gas becomes higher than a predetermined pressure. Wen the pressure becomes higher than that of the elastic force of the valve spring 173, the discharging valve 172 is moved.

[0042] At this time, the pressure supporting surface 172A of the discharging valve 172 is opened, and the compressed gas is discharged to the compression space P2 through the opened gap.

[0043] The gas which is discharged to the compression space P2 is discharged through the gas discharging pipe DP which is connected to the discharging cover 171.

[0044] When the pressure of the compression space P1 becomes lower than a predetermined pressure by moving the compressed gas to the compression space P2, the discharging valve 172 is restored to the original state by the elastic force of the valve spring 173, and the sequential process of sucking and compressing the gas is repeatedly performed again.

[0045] Since the pressure supporting surface 172A of the discharging valve 172 which is protruded at a predetermined curvature is linearly contacted on the inclined discharging surface 141B of the cylinder 141, suction noise can be reduced by reducing the contact area.

[0046] Also, in case the process of suction, compression and discharge is repeatedly performed for a long time, the discharging valve 172 can be deformed by abrasion by friction and pressure difference of the compression spaces P1 and P2.

[0047] At this time, since the pressure supporting surface 172A of the discharging valve 172 maintains a linearly contacted state with the inclined discharging surface 141B, the opening and closing performance of the discharging valve can be maintained.

[0048] As described above, the present invention can improve the compressing performance by maintaining opening and closing performance even though the discharging valve is deformed by using the valve for a long time, and the discharging valve and cylinder are linearly contacted, thus to reduce suction noise.

[0049] As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims. 

What is claimed is:
 1. A reciprocating compressor, comprising: a piston which performs a reciprocating movement by receiving a driving force of a reciprocating motor; a cylinder in which a piston is inserted to form compression spaces therein together with the piston, and a inclined discharging surface is formed at the end surface; and a discharging valve assembly including a discharging cover which is combined with a side of the cylinder, a discharging valve which is installed at an end of the cylinder to adjust gas discharge in the compression spaces and a valve spring for elastically supporting the discharging valve.
 2. The compressor of claim 1, wherein the rear surface of the discharging valve is positioned to be linearly contacted on the inclined discharging surface.
 3. The compressor of claim 1, wherein the inclined discharging surface is adjacent to the inner circumferential surface of the cylinder.
 4. The compressor of claim 1, wherein a pressure supporting surface which is contacted on the inclined discharging surface is protruded and formed at a predetermined curvature. 